Yes there are differences, how could there not be? No they are not prescriptive - science is descriptive, not prescriptive - individuals can do whatever the hell they want and are able to do. Whatever differences there are, as with height, will manifest as medians and averages on bell curves, not as predictions or prescriptions for any individual. Understanding homo sap thru science is a great idea. Politicizing and weaponizing every small, and maybe not replicable study, in the interest of one agenda or another, is not a great idea.